Problem/Motivation
Originally the \Drupal\Core\Config\ExportStorageManager
was dispatching the transformation event only when needed. For that reason it was listening to events related to configuration changes. In #3077504: Add config_exclude functionality to core we added StorageRebuildNeededEvent because sometimes things might change that are not just dependent on the active configuration.
In the patches for #2991683: Move configuration transformation API in \Drupal\Core\Config namespace (in particular #43) we found out that all the moving parts for this cause some unnecessary trouble with the installer.
Proposed resolution
Less moving parts but dispatching of transformation event more often.
This makes the API more concise. Importing and exporting configuration is a relatively rare event so this does not have a negative impact on site performance.
Remaining tasks
create patch
review
commit
User interface changes
none
API changes
very recently added (in experimental module) event is removed again as it becomes unnecessary.
Data model changes
none
Release notes snippet
n/a